Production of artificial products by dry spinning



Patented Apr. 2 1935 '1 ITE c v SPINNING I M l Henry Dreyfus, London, England v 1f No Drawing." Application l\'-Iay5, 1931,\Serial Noj 535,2 4. ln'qreat Britain July 4,1930 7 16 Claims.

'I'hls'invention is a continuation in part ofthe inventions-of my prior-U. S. applications 8. Nos.

7 328,305 filed 24th-De'cember, 192s and 444,621 filed 15th April, l930and-relates. to the manufac- 5 ,ture of artificial filaments, threads, ribbons, films .or other products from solutions-containing cellulose acetate or other cellulose esters orethers by the dry spinning method;

I I said U.- S. application Sl No. 328,305 descmbes the production of 7 improved artificial filapossible to obtain-products.ofsubstantially increased extensibility or elasticity,- and in'particular low filament deniers are obtainable. v

, My said U. ,8. application S. No.-444,621 describes the production of; products bydryspinning .solutions of cellulose esters or ethers in a mixture comprising a volatile non-solvent medium (comprising a volatile, solvent and a higher boiling non solvent) and ahi'gher boiling; solventor sol- .vents. in suificient quantity to confer solvent properties upon the whole medium.

, hav now ound t u b ar s i iev/b obtained by replacing or partly replacing the non- ,3 solvent liquid in the spinning solution by vapours v:ofsuch non-solvent liquid. in the-evaporative medium, andaccordingly the present invention comprisesa process for-theproduction of artificial filaments,-threads,' ribbons; films or otherproducts fromsolutions-ofcelluloseacetate or other cellulose esters or ethers ina solvent mixture containing a volatile substance'or substances and 5 a higher boiling solvent or solventswith or without non-solvent liquids intoan evaporative medium, for example air, containing vapours of a non-solvent liquid, for example water, benzene,- x lene, methyl, 'ethylor -propyl alcohol or mixtures thereof. 1

The specifications referred to. above contain a number of examples of suitable, volatile substances for making up the spinning solution and of higher boiling solvents therefor. Diethyl phthalate,

ethyl lactate, lactic acidsdioxaneand diethyl tarsuitablehigher boiling solvents.

m ats, threads,'or likeprodu ctsby the dry spin- I As already indicated, in, addition to the jva'pours ofa non-solvent liquid being present the evaporative medium such a .non-solvent'megiium $1,996,102 I :5 BRODfiCTEN 0F RTIFICIAL PRODUCTS BY may also be present in the spinning solution itself.

Furthermorethe evaporative medium mayinclude vapours of asolvent for the cellulose derivative, for example vapours of acetone, The presence of these solvent vapours, in addition to those prov v duced from the filaments themselves is also f value in producing very fine filament deniers.

; boiling solventbe not greaterlthan about. 5 0ito 100% of theweight of the cellulose acetate or other ester or ether and preferably not.v greater than about 3()% there of..-'Again if a nonavant liquidbe included in'the spinning solution its prof- It is-preferredthat) the proportion Qfhighr portion should'not be sufficient to approach the stage of, precipitation or incipient precipitation before spinning and. is preferably, not sufficient to produce a "precipitated actual spinning. j V

The temperature and. rate of flow of the air or other evaporative medium may be adjusted to obtain 'any'desired'tylp'e or form of filament isolid,

product "during the hollow etc.) hor cross-section 'of filament;{TIhesize of" the .jet holes'may be'adjusted in accord;

ance with'the spinning requirements; Fora-ex ample, whenv running at. relatively high: spinning speeds; smaller jet'holes, e. g.of-l08;: to-,05, even down to .01 diameter, may be used than" with moderate or 10w. spinning speeds. Again,

with .thehigher speeds, higher concentrations of solvent vapour in the evaporativefmediumare permissible than with'lower speeds of 'spinmng toobtain products having similar; physical char'- 4 acteristics, thus'with the higher spinning'speeds .f

one may employ a smaller flow of evaporative medium. Furthermore these factors or other denier beingproduced.

substantially eliminated from thefilaments'for .other products in one ope a pi e p f I process being carried out, if,- desired,,withpasultable tension applied-direct from' The products which still contain higher'boihpg solvents'may be further drawn out, as fore);- ample between two rollers or other devices rotating at different peripheral speeds} The 1 ztion further includes processes inwliichsfuch' additional tension or stretch is impartedtogthe plete elimination of the solventmixture,

filaments or other products before thei com- I the volatile constituents, of I renew easem or other products may be subjected to a dry spin- I ning operation to eliminate a substantial proportion of the volatile constituents of thesolvent mixture, the said operation being conducted undertension or not as desired, and the filaments or other products, still in a plastic state due to their content of higher boiling solvents and lower boiling? be stretchedor inrther stretched ia's "previoufly described; stretch filaments or other products by means 'of' a roller, guide, or tension device which ofiers resistance, to their passage as describedfoi' esia'ms e in; S} application's. No. 476,334 filed 19th August, 1930.

but are not to be considered as limitingitjin.

Example 1 v A spinning solution I is made up containing 2'? pwsior:eemmeiacetat dissolved in a mixture BT65 parts oiace'tonejandi! parts of ethyl'lactate or'diacetoiie alcohol." The solution isspun into h an evaatmfi emeu um maintained t, .a' temperature "6170' to"80 C. and having ajmoisture o co eiit cot-responding to' saturationat.atemperature 45 to 5'5" 'C. The iilaments'mayieither be subjected to tension direct mm the nozzle, or as described in usqap licano s. No.-4 16', 334 such'jteiision may" be wholly, or in part confined toithelatejr s'tag'sotthe" spinning; Ai'ter sub.-

; Aspinningsolution is made-up contain 2'5 parts of cellulose acetate; "7 parts of water 8 parts ofethyl lactate and 60 parts of acetone, I c and-is spun]- as described inExample 1 or 2.v V

Erample if A spinning solution ismade up containing parts of cellulose acetate, fiopar'ts of acetone,;18 parts of alcohol and 7 parts of ethyl" lactate or c1 a i e alcohol; and is glijlos'e acetate may also be appliedto'the inanuiacture of products from solutions of other opionate orbutyrate or ofcellulose ethers; for 'instancemethyl, eth'ylor bench cellulose or other cllulosethersl jp What I claim and 'desiretd-secure by [letters Fit in -1S v -r.-'-'rrocess for the productieiiiof arsenal mmay be restricted to the desired portion of the The following examples i1lustratetle iiiveritioii- 'eliniination oi the volatile solvent the filam bf'e" iurtherf stretched, as for ex-' 7 "ess rorme'pmauaios" j e mvemibn is sarucmariy valuable in the cafs oi! obtaining, products-from solutions :01 cel- I j lulose acetate and especially acetone+soluble cela c umose esters, for, example cellulose-inmate, .7 'p

terials'comprising dry spinning a solutionof a cellulose derivative in a mixture comprising a volatile solvent and a higher boilingsolvent into an evaporative medium charged with, the vapors of a substance whichis a non-solvent for the cel-,

lulose derivative.

' 2. Process for the production of artificial masolvent and a higher boiling solvent into an evaporative medium charged'with the vapors of agsubstanccwhich is a non-solvent for the cel- 3f Frocess i or the production of artificial materiais eompnsmg dry spinning asolution of a cellulose. derivative inc mixture comprising a volatile anss -Kighr boiling solvent into an evaporative medium charged with the vapors of a shbteiie'e which is a non-solvent for the cellulose erivative and stretching, the product fl cirmea: -c H A *4. for the production oi I 'terials comprising" aflsoiuttonfiqi cellulose acetate in a-mixture comprisinga tile solvent and" a l'righer'bolling solvent into an evaporative medium v pq "substance" which is a non-"solvent for; celilflose acetate and stretchin t pmdfictfprmed;

5. Process according 'to cl'iairn 2, 'whereinfthe higher boiling solventfispres'ent' in apropor'tion not exceeding oi' the cellulose acetate: H p I 1;. v 6;;I-Process for the productionoi artificial" substance which isa nqn solvfeiit'io'r 'cellulo derivative;

r cm r e r a sn u n'i'ois cellulose j derivative in s mmers-l mma a volatile solvent, a higher? boiling'i'solvent. arid "a; hon-solvent for the celh lose de flvative inman evaporative m iu'm chaigedwith the vapors ofa terials comprising a sohitibhbfla cellulose derivative a "comp i ing T volatile solvent'iand a'l'ifi'ghefboiiingfsolventinto "an evaporative medium'charged'withthevapors "of a substance which ;is-'-a*-non-s6lvent tor-the cellulosederivative snags m n mums swam- Process 'ifortheproduetion' tcrials comprising afsolutio oi I wan-nose acetate in amemire ompnsmga tile solvent and a higher boiling solvent int an 1 v evaporative medium charged with the vaporsof a substance which is a non-solventior the cellulose acetate and is miscible with saidmixture.- 1

9. Processi'or the' production of'artiflcial' mi}.-

terials comprising "dryspinning a solution of a cellulose derivative-in a mixture comprisin'gfa volatile solvent, 9.; higher boiling-"solvent and a non-solvent for the cellulose derivative into an evaporative medium charged withthe vapors of a 'substance'whichis a non-solvent io'r'the cellulose derivative and is miscible 'wlth said nuxture;

' 10. Process for the'production or artificial materials'" comprising v dry. Spinning a solution oi cellulose acetate in a mixture comprising acetone and a higher boiling solvent'into an evaporative medium charged with the vapors of a substance which is, a non-"solvent for the cellulose derivative and'is miscible with said mixture;

' 11. Process for the prod man of artificial amt'erials comprising dry spinning, a solution of cellulose acetate in a mixture comprising-vavolatile orative medium charged with watcr 'vapon solvent and a higher boiling solvent into anevap- 12. Process for the production of artificial materials comprising dry spinning a solution of cellulose acetate in a mixture comprising a volatile solvent and a higher boiling solvent into an evaporative medium charged with alcohol vapor.

13. Process for the production of artificial materials comprising dry spinning a solution of cellulose acetate in a mixture comprising acetone and ethyl lactate into an evaporative medium charged with water vapor.

14. Process for the production of artificial materials comprising dry spinning a solution of cellulose acetate in a mixture comprising acetone and diacetone alcohol into. an evaporatlve medium charged with water vapor. v v

15; Process for the production of artificial ma-.-

terials comprising dry spinning a solution of cellulose acetate in a mixture comprising acetone and ethyl lactate into an evaporative medium charged with alcohol vapor. i

16. Process for the production of artificial ma- 

